Apparatus for drawing glass cylinders



APPLICATION FILED AUG. 8, 1919- Patented July 20, 1920.

UNITED STATES PATENT OFFICE.

PENNSYLVANIA, ASSIGNOR TO CON- BRADFORD, PENNSYLVANIA.

APPARATUS FOR DRAWING GLASS CYLINDERS.

Specification of Letters Patent.

Patented July 20, 1920.

Application filed August 8, 1919. Serial No. 316,148.

To all whom it may concern Be it known that I, LAURENCE E. STEW- ART, acitizen of the United States," and a resident of Bradford, in the county of Mo- Kean and State of Pennsylvania, have in; vented certain new and useful Improvements in Apparatus for Drawing Glass Cylinders; and I do'hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in the art to which it appertains to make and use the'same. 1

My inventionrelates to an improvement in apparatus for drawing glass cylinders and particularly to means for gradually 1ncreasing the pressure of air for holding the cylinder distended as the draw progresses, and it consists in the parts and combination of parts as will bemore fully explained and pointed out in the claims. I

In the accompanying drawings; Figure 1 is a diagrammatic view of circuits and controlling devices for use in a'cylinder drawing apparatus; Fig. 2 is a view showing the bait hoist and the automatic rheostat mechanically connected with the same; Fig. 3 is a view showing the cage 5 carrying the fan and its motor and also the bait tube and bait, and Fig. 4 is a view in plan of a portion of the mechanism shown in Fig.2.

This invention is designed for use with a drawing apparatus wherein a blower fan 5 for supplying air to the interior of the cylinderis carried in a cage 5 which carries the drawing bait, and which also carries an electric motor5 for actuating the blower or fan. This cage 5 is'suspended from a hoist cable 6 and carries the pipe 7 having the bait 8 at the lower end thereof. The fan 5 and motor 5 are located in the cage 5, and the motor isconnected in circuit and controlled as hereinafter explained.

The cable 6 for lifting. and lowering the cage 5 isattached' to the hoisting drum 14 at one end of the shaft 15 which is mounted in a bearing 16. Securedto the end of a shaft 15, so as to rotate therewith is the worm 17 which is in mesh with the worm wheel 18 secured on shaft 19, the latter being mounted in bearin s at the u er ends of brackets 20, carried b y the l-be ffi frame of the hoisting engine. Shaft 19 carries a sprocket wheel 21 which is connected with sprocket wheel 22 on the shaft 23 of the automatic rheostat 24, by the sprocket chain 25, so that said shaft, which carries the movable contact arm 26 rotates or turns with the hoist drum 14. A manually operable rheostat 29 is also employed, and the circuits and devices for controlling the operation of the fan motor will now be described. The mains or leading-in-vvires are connected with a main switch 13. The contact w of this switch is connected by a conductor a with one terminal of the manually operable rheostat 29, and the other terminal of this rheostat is connected by conductors a and a with one end of a fixed resistance b-the other end of said resistance being connected with one end of the series of resistance elements of the automatic rheostat 24. The movable arm 26 of this rheostat is connected by a conductor a with one of the commutator brushes 5 of the fan motor 5*, and the other commutator brush 5 of this motor is connected by a conductor 0 with the contact 1 of the main switch. The field coils of the fan motor (indicated at d) are included in a shunt circuit with lamps al included in parallel in said shunt circuit. The shunt circuit may be traced from the conductor a, by a conductor 6 to the parallel circuits of the lamps d and from said parallel circuits, by a conductor 6 to one terminal of the field coils (Z, the other terminal of the latter being connected by a conductor 6 with the conductor 0 The conductor a is connected by a conductor f with the movable member of a manually operable high speed switch 9, and the stationary contact of this switch is con nected by a conductor with a resistance element of the automatic rheostat 24, which is intermediate the ends of the series of resistance elements of this rheostat.

It will be apparent that under normal conditions, when the high speed switch is open, both rheostats will be included in series with the armature of the fan motor, and that when the high speed switch 9 is closed, the fixed resistance 6 and a portion of the resistance elements of the automatic rheostat will be short-circuited.

I It will 'be seen that. when the hoist drum 14- is rotated, the arm 26 of the automatic rheostat 2 L will be moved simultaneously through the gearing described, the ratio of speeds being so arranged that the arm of the rheostat will travel slightly over one half a revolution during the drawing of one cyl inderi As previously explained, the small fan 5 carried by the cage 5 and driven by an electric motor 5", supplies the air to thein terior of the'cylinder. Experiencehasdemonstrated that at'ter the cap of the cylinder 7 hasbeen formed, a gradual increase in the pressureor' air is required'to'keep the cylinder properly distended as the draw progresses. It is evident that any increase in the electric current furnished the fan motor will increase the speed of rotation oi' the motor, thus increasing the volume and pressure of air supplied to the cylinder being drawn, hence it will be seen that by supplying the current to the fan motor through the automatic rheostat 24, which cuts out the resistance progressively as the drum .14 winds up thehoist cable, the amount of current so supplied to the' fan motor will be I formthe' neck and cap. The same resultcan be accomplished by closing the, high speed switch .9 so that (the-fixed resistance (Z and a portion of the resistance of the rheostat 24.- will be'short-circuitech) The high. speed switch,,which "is located in the operators pulpit is normally open and is only closed momentarilyv when extra volume or pressure of air is needed and is not as. a rule kept closed for any appreciable length oi time.-

At times when'the surface glassis cool, all the voltage obtainable may be required for the neck and cap, and during the draw when the operator sees that themeni'scus is thickening or drawing in, additional air may be required and this can be supplied by closing the high speed switch. lVhen however' the glass is no'rmahand other conditions are correct, the high speed switch will be open so that the fan motor will be included in series with both rheostats and the fixed re"- sistance.

If the surface glass from which the cylinder is drawn could be maintained at a regular and uniform temperature and in the same condition, the automatic rheostat would be sufficient to control'the supplyof the proper amount of air to the cylinder. 7

'But this is impossible, hence when the glass is stiff, more of "the resistance can be cut out of the hand operated rheosta't thus start 7 ing the automatic rheostat with higher initial voltage. If; on the other hand the glass be soft, not so much air would'be .re-

quired and the iinitial voltage through the automaticrheostat couldbe reduced by in creasing the. resistance to the current in its passage throughthe hand operated rheostat.

- Having fully-described my invention what I claim as new. and desire-tosecure-byLeh ters-Pate'nt, is t v 1. The combination with hoisting means, a fanand-an electric motor fort-lie fan, of 'an'electric'icircuit;including said motor, a rheostat operable automatically by the hoisting means, a manually operable rheostat, said rheosta'ts;beinglincluded in series in the motor circuit, anda switch. for-exclud- -1ng -a :portion of the =1'6S1St2LIlCB elements of one of: said rheostats from'the motor circuit.

. 2. The-combination .with hoisting means for the'bait, a fan for supplyingair t'o'the cylinderbeingdrawn, and an electric motor for said'fan, of an elec'tric circuit including said motoigja rhcostat operable automaticallyby the hoist means,='a manuallyfloperable rheostat, means for includingboth rheostats in series with each other'and with said motoryand a switch forwshortcirc'uiting a portion of the resistance "elements" of the automatically operable rheostat.

The combination with hoisting means for the lbait a fan'for supplying air to the cylinder being drawn,fan'dan'electric motor for sald fan, of an electric circuitincluding said motor, a rheostat operableautomatically by the hoist means, amanually operable rheo'stat, means "for including both rheostats in series with each other and with said motor, a circuit short circuiting a portion-of the resistance of the automatically controlled'rheostat, a switch insaidcircuit,v

and a fixed resistance in'serie's with both rheostatsan'd the motor;

4. The-"co "bination' with lioistingmeans for the bait,- a fan for supplying airto the cylinder: being drawn, 1 and anelectric zmotor for the: fan, of an electric- .circuit' including the armature ofthe motor, an automatically 1 operated rheostat, atmaiiually' operated rheos tat and a fixed resistance included in SLlCl' circuit 1n series wlth 'each other and .with the armature'of the inotor,fa shunt circuit including the field coils of the motor, In testimony whereof I have signed this fixed resistance in said shunt circuit, a short specification in the presence of two subscribcircuit around the first-mentioned fixed reing Witnesses.

sistance and a portion of the resistance ele- LAURENCE EDWIN STEWART. ments of the automatically operated rheo- Witnesses: stat, and a manually operable switch in said WM. E. BURDIOK,

short circuit. FINETTA E. MCFADDEN. 

